agentic-sx Phase 3: trace — console output as attached CID objects (TDD)

Per-agent buffer = persist append-only log stream + kv drain cursor;
commit-with-trace! drains everything-since-last-commit into a console-trace
object and binds it git-note style (ref notes/trace/<commit-cid> -> trace
cid). Trace never enters the commit tree; binding is a re-bindable ref layer
over immutable objects; failed commits keep the buffer; plain commit! leaves
binding to the agent. 35/35 (153/153 total).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

lib/agentic/scoreboard.json

@@ -1,9 +1,10 @@
 {
   "suites": {
     "schema": {"pass": 65, "fail": 0},
-    "branch": {"pass": 53, "fail": 0}
+    "branch": {"pass": 53, "fail": 0},
+    "trace": {"pass": 35, "fail": 0}
   },
-  "total_pass": 118,
+  "total_pass": 153,
   "total_fail": 0,
-  "total": 118
+  "total": 153
 }